JP3286038B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using a non-azeotropic mixed refrigerant as a refrigerant.

[0002]

2. Description of the Related Art Generally, an air conditioner is composed of a compressor, a use side heat exchanger, a decompression device, and a heat source side heat exchanger. In a cooling mode, the use side heat exchanger is used as an evaporator. The heat source side heat exchanger is used as a condenser. In the heating mode, a refrigeration cycle is configured in which the use-side heat exchanger is used as a condenser and the heat-source-side heat exchanger is used as an evaporator, and the refrigerant circulates in the cycle.

[0003]

The refrigerant circulating in the refrigeration cycle generally uses chlorofluorocarbon gas and tends to be completely eliminated from places that have a bad influence on the global environment. Boiling mixed refrigerants are considered promising.

[0004] The non-azeotropic refrigerant mixture has a phenomenon that in the refrigeration cycle, the evaporation temperature and the condensation temperature change in the evaporation process and the condensation process due to the difference in the boiling point of each refrigerant. This is called a temperature gradient.

[0005] In the evaporator of the refrigerant circuit, the refrigerant liquid becomes refrigerant vapor while maintaining the gas-liquid equilibrium. During this time, the evaporation temperature gradually rises. In a condenser, the opposite is true, and the condensation temperature gradually decreases. On the other hand, the air is deprived of heat in the evaporator and becomes low temperature, and the air gains heat in the condenser and becomes high temperature. Table 1 summarizes these temperature relationships.

[0006]

[Table 1] The refrigerant circuit of the non-azeotropic refrigerant, the heat exchange loss by performing heat exchange counter-current system, the phase temperature change by utilizing the characteristics depending on the concentration refrigerant cold air fluid or heating fluid, And the coefficient of performance can be improved. The pair countercurrent system, relative to the air flow, is in the entrance is most leeward column of refrigerant, in the outlet is most windward column, to flow in the column sequentially upwind from leeward column of refrigerant It means when it is arranged. In the case of this reverse are called concurrent flow type, when used as a condenser, JP and pairs countercurrent 53
-104456 Patent and Publication, cooling mode, JP be configured to be paired countercurrent heating mode 59-115945
And JP-A-63-302264 have been proposed.

However, in the former case, when the use side heat exchanger is used as a condenser, if it is set as a counter flow, the flow becomes parallel when used as an evaporator, so that the heat exchange efficiency in the cooling mode is reduced. This leads to a deteriorating problem.

In the case of the latter, the number of control valves and circuits for controlling the flow of the refrigerant is increased and complicated, which is not desirable in terms of assemblability and cost, and is complicated. There is a problem that efficiency loss occurs due to the above.

When a refrigerant having a temperature gradient is used,
Matters that must be considered, in addition to changes in the net heat transfer phenomena heat exchange rate by pairs countercurrent or parallel flow, when used as a heat exchanger for cooling air (evaporator), water vapor of the cooling air It is necessary to consider the decrease in the amount of heat exchange due to the decrease in the amount of ventilation due to the increase in the ventilation resistance due to the condensation of the air. Water vapor in the parallel flow air where the difference between the fin and the inlet air temperature in the evaporator becomes large condensed and condensed on the front end surface of the fin, narrowing the passage between the fins, and reducing the amount of heat exchange due to the decrease in air volume . Conversely, it is known that, in the case of the opposed flow which becomes smaller, the amount of dew condensation on the front end of the fin is smaller than that of the former, and the dew condensation is more averaged from the center to the rear end.

Accordingly, an object of the present invention is to provide an air conditioner capable of performing efficient cooling and heating operations without reducing the amount of ventilation and without complicating the circuit of the refrigeration cycle.

[0011]

To SUMMARY OF THE INVENTION To achieve the above object, the present invention is use as an evaporator of the exchanger to the cold tufts mode or heating mode, or a non-azeotropic mixed refrigerant used as a condenser There was Te air conditioner smell, the heat exchanger for use as a coagulation condenser, to the air flow passing through the heat exchanger, while the parallel flow provided with the inlet side of the coolant on the windward, the outlet side of the refrigerant Is arranged on the windward side, so that the outlet-side refrigerant partially flows in the counterflow . Alternatively, the heat exchanger used as the evaporator is provided with a part of the inlet side of the refrigerant on the windward with respect to the air flow passing through the heat exchanger, and the inlet side of the refrigerant at the upstream side from the outlet side of the refrigerant. It is arranged at a position adjacent to the heat tube.

[0012]

According to this air conditioner, a temperature gradient is generated.
The inlet and outlet sides are located on the windward side,
The zone is countercurrent and condenses when acting as a condenser.
The refrigerant at the contraction outlet exchanges heat with air having a low windward temperature.
As a result, the subcooling is efficiently performed, and the cycle efficiency is improved. Further
In addition, when acting as an evaporator, the inlet and outlet areas
Are averaged. So for example, low temperature
Frost, freezing phenomenon, or
Indicates that the moisture condensation phenomenon is eliminated, resulting in an efficient ventilation
Can be secured. Also, close to the lowest heat transfer tube on the inlet side.
Since the outlet side of the evaporator is arranged in contact with the
Effect is reduced and the loss of cooling capacity is kept small.
You. Therefore, the fin temperature on the inlet side rises and
Fin temperature efficiently
This has the advantage of averaging.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 shows that refrigerants such as R32 and R134
1 shows a heat pump type air conditioner using a non-azeotropic mixed refrigerant such as a.

The air conditioner includes a compressor 1, a use side heat exchanger 3, a pressure reducing device 5, and a heat source side heat exchanger 7.
By operating the four-way valve 9 in accordance with the cooling / heating mode, the refrigerant discharged from the compressor 1 is directed to the use-side heat exchanger 3 as indicated by a dotted arrow, or to the heat source-side heat exchanger as indicated by a solid arrow. A refrigeration cycle having a flow toward the side 7 can be obtained, and switching control corresponding to the operation mode can be performed.

The use side heat exchanger 3 includes a continuous heat transfer tube 11
And the fins 13 arranged at a predetermined pitch. The refrigerant functions as an evaporator when the refrigerant flows in the circuit 15 as indicated by a solid arrow, and functions as a condenser when the refrigerant flows as indicated by a dotted arrow. . The air flow cross flow fan 17 arrow如 rather flow by rotating, being adapted to pass between the fins 13, a side is windward side, b side and downwind side.

A terminal 19 on the upstream side of the heat transfer tube 11 of the use side heat exchanger 3 is connected to the four-way valve 9, and a terminal portion 21 on the downstream side b of the heat transfer tube 11 is connected to the pressure reducing device 5. Communicating. Thus, in the cooling mode, the terminal portion 21 on the leeward side b is connected to the terminal portion 19 on the inlet side of the refrigerant and the leeward side a.
Is set to be a counter flow on the outlet side, and in the heating mode, the terminal portion 19 on the upwind side a is at the inlet side of the refrigerant,
The terminal 21 on the side is set to be in a parallel flow on the exit side.

The heat source side heat exchanger 7 includes a continuous heat transfer tube 23
And the fins 25 arranged at a predetermined pitch. The refrigerant functions as a condenser by flowing through the circuit 15 as indicated by a solid arrow, and functions as an evaporator by flowing the refrigerant as indicated by a dotted arrow. The air flow flows as indicated by the arrow as the fan 27 rotates, and passes between the fins 25, with the a side being the leeward side and the b side being the leeward side.

A terminal 29 on the windward a side of the heat transfer tube 23 of the heat source side heat exchanger 7 is connected to the four-way valve 9, and a terminal 31 on the leeward b side of the heat transfer tube 23 is connected to the pressure reducing device 5. Communicating. Thus, in the cooling mode, the terminal section 29 on the leeward a side is set to be in parallel flow with the inlet side of the refrigerant and the terminal section 31 on the leeward side is in the outlet side. In the heating mode, the terminal section on the leeward b side is set. Numeral 31 is set to be a counterflow in which an inlet side of the refrigerant and a terminal section 29 on the windward a side are an outlet side.

In the air conditioner configured as described above, in the cooling mode, the high-temperature and high-pressure refrigerant vapor discharged from the compressor 1 enters the heat source side heat exchanger 7 through the four-way valve 9 and outputs the outdoor air. Heat and condense. The condensed refrigerant is decompressed by the decompression device 5, becomes low temperature and low pressure, and absorbs heat from indoor air in the use side heat exchanger 3 to be vaporized. The vaporized refrigerant is sucked into the compressor 1, becomes high-temperature and high-pressure steam again, and repeats the refrigeration cycle. On the other hand, in the heat pump heating mode, the high-temperature and high-pressure refrigerant vapor discharged from the compressor 1 first enters the use-side heat exchanger 3 via the four-way valve 9 and radiates heat to room air to be condensed. The condensed refrigerant is decompressed by the decompression device 5 and becomes low temperature and low pressure, and the heat source side heat exchanger 7 absorbs heat from outdoor air and vaporizes. The vaporized refrigerant is sucked into the compressor 1, becomes high-temperature high-pressure steam again, and repeats the heating cycle.

In the cooling mode and the heating mode, in the operation mode in which both the use-side heat exchanger 3 and the heat-source-side heat exchanger 7 are used as evaporators, the flow becomes counter-current and the flow as the condenser. When used, it is a parallel flow. In this case, since the temperature difference between the inlet side and the outlet side is small in the evaporator having the counterflow, the amount of water vapor dew condensation on the front end of the fin is suppressed to be small as a whole, and no decrease in the ventilation amount is observed. In this way, the cooling and heating operation with high efficiency can be performed comprehensively.

FIG. 2 shows the results. In FIG. 2, in the condenser, the flow becomes parallel due to the configuration and becomes negative, but this is a value that can be recovered by increasing the number of fins.

Generally, when the number of fins is increased, the ventilation resistance increases when used as an evaporator, and the performance is reduced. However, in the present invention, the flow rate is increased by using the counter flow. Therefore, the performance when used as a condenser can be sufficiently improved.

FIG. 3 shows a modification of the arrangement of the inlet and outlet sides of the refrigerant, in order to improve the amount of air flow and at the same time to supercondensate the condensed liquid when acting as a condenser, thereby improving the performance of the condenser. Fig. 4 shows an embodiment to improve. That is, the heat transfer tube 1
The terminal portions 19, 21, 29, 31 of the heat transfer tubes 11 are arranged on the windward a side, and one terminal portion 19 of the heat transfer tube 11 is connected to the four-way valve 9.
And the other terminal unit 21 is connected to the decompression device 5. One end 29 of the heat transfer tube 23 is a four-way valve 9.
And the other terminal unit 31 is connected to the pressure reducing device 5, respectively.
When using the heat exchangers 3 and 7 on the utilization side and the heat source side as a condenser, the inlet side of the refrigerant is made parallel to the air flow on the windward a and the outlet side of the refrigerant is the windward a Placed on the side,
A part of the outlet side region is used as a counter flow.

The other components are the same as those of the above embodiment, and the same reference numerals are used and the description is omitted.

According to this embodiment, the inlet side and the outlet side where the temperature gradient is generated are located on the windward side a, and a part of the outlet side is in the opposite flow, so that the condenser is not condensed when acting as a condenser. The liquid outlet refrigerant exchanges heat with air having a low windward temperature,
Efficient supercooling improves cycle efficiency. further,
When acting as an evaporator, the fin temperatures in the inlet and outlet regions are averaged. Therefore, for example, during low-temperature operation, frost generated on the inlet side, freezing phenomenon, or,
As a result of the elimination of the moisture condensation phenomenon, an efficient air flow can be ensured.

On the outlet side, which is located on the windward a side and is in the counterflow, the supercooling can be reliably taken, and the performance can be improved.

In this case, by adopting the means shown in FIGS. 4 and 5, the capability can be further improved. That is, the terminal portions 19, 21, 29, 31 of the heat transfer tubes 11, 23 are moved upwind a.
On the heat transfer tube 11 side, each terminal portion 19,
The heat transfer tubes 11 are arranged apart from each other, and one terminal portion 21 is disposed adjacent to the heat transfer tube 11 on the windward side a. On the other side of the heat transfer tube 23, the terminal portions 29 and 31 are arranged apart from each other, and one terminal portion 31 is provided adjacent to the heat transfer tube 23 on the windward a side, and the use side and the heat source side. When the heat exchangers 3 and 7 are used as evaporators, the inlet side of the refrigerant is parallel to the air flow provided on the windward side, and the outlet side of the refrigerant is arranged on the windward side a. The outlet side region is a counter flow.

The other components are the same as those in the above embodiment, and the same reference numerals are used and the description is omitted.

According to this embodiment, in addition to the effect of the embodiment of FIG. 3, since the evaporator outlet side is disposed close to the lowest heat transfer tube on the inlet side, the influence of heat from the inlet side is reduced. And the loss of cooling capacity is kept small. Therefore, as shown by the solid line in FIG. 6, there is an advantage that the fin temperature on the inlet side increases and the fin temperature on the outlet side decreases, so that the fin temperatures can be efficiently averaged.

[0031]

As described above, the air of the present invention is
According to the harmony device, when acting as a condenser, the condensate
The outlet refrigerant exchanges heat with air having a low windward temperature,
It is supercooled efficiently and the cycle efficiency can be improved. Further
At the inlet and outlet side when acting as an evaporator
Since the fin temperatures of
Mouth-side frost, freezing, or moisture condensation
As a result, the efficient ventilation can be secured.
In addition, at the outlet side, which is the opposite flow side,
Indeed, performance can be improved. In addition,
The evaporator outlet side should be located close to the low heat transfer tubes
In this way, the effect of heat from the inlet side is eliminated and the cooling capacity is lost.
Fins on the entrance side
As the temperature rises and the fin temperature at the outlet decreases,
The fin temperature can be averaged efficiently.
You.

[0032]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a refrigeration cycle of an air conditioner according to the present invention.

FIG. 2 is an explanatory diagram showing a change in efficiency due to only a temperature gradient between an evaporator and a condenser and a change in efficiency due to ventilation resistance when a counter flow and a parallel flow are used.

FIG. 3 is an explanatory view similar to FIG. 1 showing an embodiment in which an inlet side and an outlet side of a refrigerant are provided on the windward side of an air flow;

FIG. 4 is an explanatory diagram similar to FIG. 3, showing an example of changes on the inlet side and the outlet side of the refrigerant.

FIG. 5 is an explanatory view of a partial heat exchanger showing still another modification of FIG. 4;

FIG. 6 is an explanatory diagram showing temperatures at an inlet side and an outlet side of a heat transfer tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 User side heat exchanger 5 Pressure reducing device 7 Heat source side heat exchanger 9 Four way valve a Upwind b Downwind

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F25B 39/04 F25B 39/04 E (72) Inventor Yasuhiro Arai 8-8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Living Space Systems Technical Research Institute (72) Inventor Takayoshi Iwanaga 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Corporation Living Space Systems Research Institute (56) References JP-A-58-62469 (JP, A) 108967 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 13/00 F25B 1/00 F25B 39/00-39/04 F28F 1/32

Claims (2)

(57) [Claims] In a cooling mode or a heating mode, in an air conditioner using a non-azeotropic mixed refrigerant which uses a heat exchanger as an evaporator or as a condenser, a heat exchanger used as a condenser includes: With respect to the air flow passing through the heat exchanger, the inlet side of the refrigerant is made a parallel flow provided on the windward side, and the outlet side of the refrigerant is arranged on the windward side, so that the part of the refrigerant on the outlet side becomes a counterflow. An air conditioner characterized by: 2. A heat exchanger used as an evaporator is provided with an inlet side of a refrigerant on the windward side with respect to an air flow passing through the heat exchanger, and has a refrigerant inlet side transmission upstream of the refrigerant outlet side. The air conditioner according to claim 1 , wherein the air conditioner is disposed at a position adjacent to the heat pipe.